The movements of people suffering from dementia or mental disorders in hospital buildings, nursing institutions, service homes, their wards or in corresponding premises can be monitored by means of a wristband attached to the person's wrist. The wristband may have a wireless radio connection to base stations in the building, which may be part of an exit and access control system. A display in a control room of the system may show the ongoing situation in the building by means of a graphical representation. The system may alert the control room, if someone removes the wristband from his or her wrist, tries to open a door, the opening of which is prohibited to him or her, or tries to use an elevator, the use of which is prohibited to him or her. The control room can inform the personnel of the institution in general, where the alarm has been triggered and, depending on the characteristics of the wristband, possibly also who has triggered the alarm.
However, there are problems involved with this type of control system. Having the wristband on the wrist or in some way with you all the time is not very comfortable for the person being monitored, and many refuse to use it, or try to take it off as soon as possible. In some cases, taking the wristband off may be necessary due to treatment or some other reason, and if the person being monitored forgets to put is back on the wrist, s/he may unintentionally wander outside or enter forbidden locations without anybody realizing it. A reliable operation of the system is also hampered by the fact that maintaining the charge of dozens, even thousands, of wristband batteries or accumulators at a sufficient level all the time is extremely difficult, or even impossible, and the nursing staff uses a lot of time in replacing the batteries or charging the accumulators.